Conveyor system for elongated structures

ABSTRACT

A tall building has a lower first feeder or shuttle bank of elevators operating between a bottom terminal or main floor and a transfer floor. The building has a local second bank of elevators operating between the transfer floor higher floors to provide local service. A computer maintains a proper number of feeder elevators in service, distributes feeder elevator cars between the bottom terminal and transfer floors, and coordinates arrival of local and feeder elevator cars at the transfer floor. If plural feeder banks are employed the computer coordinates the service provided by such feeder banks.

United States Patent inventors Appl. No.

Filed Patented Assignee John Suozzo Hackensack;

Henry C. Savino, Hackensack, NJ. 828,555

May 28, 1969 g H u H Division of Ser. No. 526,813, Feb. 11, 1966, Patent No. 3,467,223.

Feb. 9, 197 1 Westinghouse Electric Corporation Pittsburgh, Pa.

a corporation of Pennsylvania CONVEYOR SYSTEM FOR ELONGATED STRUCTURES 9 Claims, 12 Drawing Figs.

US. Cl

[56] References Cited UNITED STATES PATENTS 2,740,496 4/ I956 Santini et al.

Primary Examiner0ris L. Rader Assistant Examiner-W. E. Duncanson, Jr. Attorneys-A. T. Stratton and C. L. Freedman ABSTRACT: A tall building has a lower first feeder or shuttle bank of elevators operating between a bottom terminal or main floor and a transfer floor. The building has a local second bank of elevators operating between the transfer floor and higher floors to provide local service. A computer maintains a proper number of feeder elevators in service, distributes feeder elevator cars between the bottom terminal and transfer floors, and coordinates arrival of local and feeder elevator cars at the transfer floor. If plural feeder banks are employed the computer coordinates the service provided by such feeder banks.

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SHEET '7 OF 7 CONVEYOR SYSTEM FOR ELONGATED STRUCTURES CROSS REFERENCE TO RELATED APPLICATION This is a division of our patent application Ser. No. 526,813, filed Feb. I 1, I966, and entitled Conveyor System for Elongated structures which is Pat. No. 3,467,223.

BACKGROUND OF THE INVENTION This invention relates to a conveyor system for elongated structures and it has particular relation to such a system wherein vehicles, such as elevators, are divided into one or more feeder banks and one or more local banks which may be located on one side of a feeder bank or banks.

It has been previously proposed that elongated structures, such as tall buildings, be provided with vehicle or elevator service operating in two stages. As applied to a tall building, the first stage includes a feeder or shuttle bank for providing express service between a lower main floor such as a street floor and a transfer floor located at a high level of the building. A second stage includes one or more local banks of elevators for providing elevator service between the transfer floor and higher floors of the building. These banks operate independently of each other. Although some time is lost in the transfer of passengers at the transfer floor, the transfer of passengers between the main floor and the transfer floor can be accomplished by a relatively small number of express high-speed elevators. This results in a very large overall saving in the space required for elevator hoistways.

SUMMARY OF THEINVENTION In accordance with the invention the banks of elevators are coordinated and the elevators in a bank are coordinated to provide sufficient operation. In a preferred arrangement, traffie information is supplied to computer equipment. This computer equipment assists in controlling the elevator system to:

I. maintain in service a proper number of feeder elevator cars to handle the existing traffic;

2. distribute the feeder elevator cars between the main floor and the transfer floor for utmost efficiency;

3. coordinate arrival of local and feeder elevator cars at the transfer floor; and

4. coordinate service provided by plural feeder banks if more than one such bank is employed.

It is therefore an object of the invention to provide an improved elevator system for tall buildings.

It is another object of the invention to provide an improved elevator system employing feeder and local banks of elevators wherein such banks are coordinated to operate at improved efficiency.

It is also an object of the invention to provide an improved elevator system employing local and feeder elevator banks having a common transfer floor for coordinating arrival of the elevator cars at the transfer floor to assure improved efficien- It is an additional object of the invention to provide an improved elevator system for tall buildings wherein the operation of plural feeder banks of elevators is coordinated for improved efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings in which FIG. 1 is a schematic view with parts in block form representing an elevator system embodying the invention; and

FIGS. 2 to 11 (including FIG. 3A) are diagrammatic representations with circuits shown in straight line form of an elevator system embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGURE 1 The invention may be applied to buildings having various numbers of floors and various floor arrangements. For illustrative purposes a building having 72 floors is illustrated in FIG. I. These floors include a main floor which may be located at the street level and a transfer floor which is assumed to be located at the 4 1 st floor. This floor also may be referred to as a sky lobby." Elevator service for the floors between the main floor and the sky lobby is provided by one or more banks of lower building elevators LBE.

Passengers desirous of travelling between the main floor and a floor located above the 41st floor or sky lobby travel between the main floor and the sky lobby in elevators located in one or more feeder banks. For illustrative purposes two feeder banks 9 and 00 are shown. The number of feeder banks and the number of cars in each of the banks depend on traffic requirements. For present purposes, it will be assumed that each of the the feeder banks has four elevator cars A, B, C and D.

For elevator service above the sky lobby, passengers employ elevators located in one or more banks. Again the number of local banks and the number of elevators in each of the local banks depend on traffic requirements. For illustrative purposes it is assumed that four local banks b, 31, D2 and 93 are employed. Each of the local banks is assumed to have six elevators A, B, C, D, E and F. The bank of elevators D is assumed to serve the floors 41 to 50. The bank I serves the 4lst floor and the floors 51 to 58. The elevator cars in this bank are arranged to run express between the 4lst and 51st floors. In a similar manner, the elevator cars of the bank 1 2 serve the 4lst and 59th to 65th floors. Finally the bank 1 3 provides local elevator service for the 4lst floor and the floors 66 to 72.

In order to coordinate the elevators of the elevator system for optimum efficiency, computer equipment is provided which includes a load index" OLI and a divisional index ODI. The load index repeatedly samples the sum of the loads of all of the cars in the feeder bank 0 that leave both the main floor and the sky lobby. Thus the load index may include a pointer BLIP which indicates on an associated scale whether the total loading is light, moderate, heavy or very heavy. This load index determines in part the number of elevators in each of the feeder banks to be kept in service. The load index further indicates when help is desired from another feeder bank. The load index additionally indicates when its feeder bank has one or more elevators available to help another feeder bank.

The divisional index indicates the difference in traffic originating at the main floor and at the sky lobby. Thus the divisional index may have a pointer BDIP which indicates on a scale associated therewith the number of cars allocated to the main floor and to the sky lobby. In FIG. 1, the pointer is in a central position indicating a balanced condition wherein the elevator cars of the bank 0 are evenly divided between the main floor and the sky lobby. Positions of the pointer displaced in a clockwise direction from the position indicated in FIG. 1 indicates that more traffic originates at the sky lobby than at the main floor and assigns a preponderance of the elevator cars of the bank 0 to the sky lobby. Conversely a posi tion of the pointer displaced in a counterclockwise direction from the position indicated in FIG. 1 indicates that a preponderance of the traffic originates at the main floor and that a preponderance of the elevator cars of the bank 9 should be assigned or allocated to the main floor. When the traffic in the feeder bank is predominantly in the up direction the divisional index also may bias the local banks to send cars to the sky lobby.

The computing equipment also senses when traffic in the local banks 4 to P3 predominantly is in the down direction. Under this circumstance, the feeder banks are biased to assign elevator cars to the sky lobby.

If traffic requirements follow a reasonably definite pattern on a time basis in repetitive cycles the computing equipment may take the form of clock mechanism for assigning car allocations and biases on a time basis. However, in a preferred embodiment of the invention, the allocations and biases are responsive directly to the traffic.

A system involving the invention now will be discussed in detail. In order to simplify the presentation of the invention it will be assumed that each of the banks of elevators is similar to the bank disclosed in the Santini and Suozzo US. Pat. No. 2,740,495 which issued Apr. 3, i956. The conventions employed in the patent also will be employed here. Thus for the bank (D the first floor of the system shown in the patent would correspond to the sky lobby. For the bank (P1 of FIG. I, no car-call-registering buttons or relays and no floor-call-registering buttons or relays would be required for a floor between the 41st and 51st floors. Similar comments apply for the bank I12 and 113 with respect to the floors which are not served by these banks.

The feeder bank also is based on the system shown in aforesaid patent. FIGS. 2, 3, 4, and reproduce certain components of the aforesaid patent with changes which will be discussed below. Components of FIGS. 2, 3, 4 and 5 which are similar to components of the aforesaid patent are identified by the same reference characters. In some cases which will be mentioned below, contacts are added to the relays which are shown in the patent. For convenience, the following components common to the aforesaid patent and to the present figures 2, 3, 4 and 5 are reproduced as follows:

D-Down switch;

E-Inductor slowdown relay; F-Inductor stopping relay; G-I-Iolding relay; LT-Lower-terminal relay; MRunning relay; MGMotor-generator starting switch; NLLower-terminal next relay; NT-Upper-terminal next relay; R--Door-control relay;

S-Floor or corridor-call stopping relay; SL- Lower-terminal start relay; ST-Upper-terminal start relay; 'IT-Upper-terminal relay; UUp Switch;

VSpeed relay;

W--Up-direction relay; X-Down-direction relay; Z-Door-safety relay; ll-Electric Motor;

l3-Traction sheave;

l5--Brake;

60-Motor-generator set; 70T-Noninterference relay FIGURE 2 FIG. 2 is similar to FIG. 3 of the aforesaid Santini et al. patent with the following exceptions:

In the patent the up switch U, the down switch D and the running relay M for the elevator A are controlled by three parallel circuits in part. A first one of these circuits, also shown in the present FIG. 2, includes in series make contacts LTl of the lower-terminal relay (the main floor in the present case) and make contacts SL1 of the lower-terminal start relay. Consequently, when the elevator car A is to start from the main floor the contacts LTl and SL1 close to energize the up switch U and the running relay M.

The second circuit, also shown in the present FIG. 2, includes in series the make contacts 'I'I'l of the upper-terminal relay and the make contacts STl of the upper-terminal start relay. In the present case, the upper terminal is the sky lobby. Consequently, when the elevator car A is to start down from the sky lobby the make contacts TH and S'Il close to complete an energizing circuit for the down switch D and the running relay M.

The third circuit employed in the patent was for the purpose of initiating starting of the elevator car A from floors intermediate the two terminals. Inasmuch as the elevator cars of the bank 0 run express between the two terminal floors, the third circuit is not here required and has been deleted. Inasmuch as the sky lobby is the upper limit of travel of the elevator car A the limit switch 63 is set to open as the car in traveling up nears the sky lobby. The limit switch 64 is set to open as the car A nears its lower limit of travel, in this case the main floor, at the end of a down trip.

As shown in the Santini et al.-patent, theinductor slowdown relay E and the inductor stopping relay F are energized by any one of a number of contacts for thepurpose of initiating a slowdown and stopping operation of the elevator car A. In the present case, only the make contacts SI are required for initiating a slowdown and stopping operatiomThe other initiating contacts shown in the patent consequently are deleted.

The up direction relay W is energized through a series circuit which includes only thebreak contacts D6 and X2, and the limit switch 66. The limit switch 66 is set to open as the elevator car A on an up trip nears the sky lobby. The patent shows similar components.

The down direction relay X is energized through a circuit which includes in series only the break contacts U6 and W2, and the limit switch 67. The limit switch 67 is set to open as the elevator car A on a down trip nears the main floor.

Similar changes are made in the circuits of the other elevators of the bank 0 and are shown for the elevator B.

FIGURE 3 The present FIG. 3 is based on FIG. 4 of the aforesaid patent. However, inasmuch as the elevator cars of the feeder bank 0 shuttle between the main floor and the sky lobby the circuits have been materially simplified.

During an up trip of the elevator car A the only stop is at the sky lobby. For this reason, the only contact segment required in the f row is the contact segment f4] for the sky lobby floor. This contact segment f4l is connected to the bus L1 and is positioned to be engaged by the brush fc as the elevator car A on an up trip approaches the slowdown distance required for the sky lobby floor. When the floor-stopping relay-S is energized it initiates a slowdown and stopping operation of the elevator car A at the sky lobby in the same manner discussed in the aforesaid patent.-

During a down trip of the elevator car A the only floor at which it stops is the main floor. For this reason, the only contact segment in the h row which is required is the contact segment hl for the main floor and this is connected to the bus Ll. During a down trip of the elevator car A, when the elevator car approaches the slowdown and'stopping distance for the main floor the brush he engages the contact segment hl to complete an energizing circuit for the stopping relay S. This initiates a stopping of the elevator car A'-at the main floor in the same manner discussed in the patent;

A car-call-registering relay 41CR and its canceling coil 41CRN are provided for the sky lobby and a car-call-registering relay lCR and its canceling coil lCRN are provided for the main floor. Each of these relays is picked up when its as-*' sociated car button is pressed and is dropped out when the.

elevator car A nears the corresponding floor in the manner floor call from the main floor. As shown in FIG. 5, of the.

above-mentioned patent, the call-registering relays are employed in controlling no-call relays 78, B78 etc. In the present case, these relays have added contacts 78-6, 878-6 etc. which will be discussed below in connection with FIG. 8.

If desired, an up floor lantern may be provided for each car at the main floor and a down floor lantern may be provided for each car at the sky lobby. These would correspond respectivet ly to the floor lanterns lUL and 6DL of FIG. 5 of the Santini et al. patent and would be similarly energized. Other components shown in FIG. 5 of the patent are not required for the feeder bank 0.

Although the doors may be operated manually, it will be assumed that they are operated as shown in FIG. 6 of the aforesaid Santini et al. patent with one exception. As shown in FIG. 3A break contacts 70T4 operated by the noninterference relay 70T are connected in series with the operating winding of the door-control relay R to prevent closure of the doors of the elevator car A for a substantial time such as 5 seconds after the car stops. The relays .QL, Q and DP of the Santini patent are not required for the feeder bank 0.

FIGURES 4 and 5 FIG. 4 reproduces the dispatching circuits of FIG. 7 of the aforesaid Santini et al. patent with two changes. In the present case, the motor 8ST is continually energized form a source represented by the conductors LACl and LAC2.

The second change relates to the provision of make contacts 02-1 of a down dispatcher expedite relay 02 in shunt with the make contacts 1SD4. As long as the make contacts 02-1 are open, the dispatcher of FIG. 4 dispatches elevator cars from the sky lobby in the same manner as in the aforesaid patent. However, if a predetermined preponderance of traffic is in the up direction from the main floor the make contacts 02-1 close to expedite the dispatch of additional cars from the sky lobby towards the main floor.

It will be understood that the upper terminal relays 'IT, B'IT, CTT and D'IT are picked up respectively as long as their associated elevator cars A, B, C and D are respectively at the sky lobby floor.

The remaining components shown in FIG. 7 of the aforesaid patent are not here required.

FIG. 5 reproduces circuits employed for dispatching the elevator cars from the lower terminal or main floor. These circuits are similar to circuits shown in FIG. 8 of the aforesaid patent except for the following change.

The only change consists of the addition of make contacts 01-1 in shunt with make contacts 1SU3. When a substantial preponderance of traffic is in the down direction towards the main floor the contacts 01-1 close to expedite dispatch of elevator cars from the main floor towards the sky lobby.

F IGURE 6 FIGS. 6 to 11 introduce a number of new relays. For convenience the following list of new relays is included at this point:

01Up-dispatcher-expedite relay; 02-Down-dispatcher-expedite relay; 0B4, 0B3, 0BAL, 0T L3, 0T L4 Divisional load relays; 0B2, 0D3,-Down-cars relay;

011, 012, 013, 014 Load-intensity relays; 0P-Period relay;

0MGAAuxiliary motor-generator relay; 0QMGl-Surplus-car relay; 0QMG2Deficit-car relay; 0RE-Auxiliary sampling relay; 0SS1-Individual load step relay relay; 0SS2-Bank load step relay;

OSSB, 0SST-Divisional step relays; 0T-Sampling relay;

U2, 0U3-Up-cars relay;

FIG. 6 shows a cycling system for producing a number of pulses corresponding to the loading of the elevator car A in the bank 0 at the start of each trip of the car. A similar cycling system is provided for each elevator car of the bank 0.

When the elevator car A is stopped at either of its terminal floors, a capacitor 0C1 is connected in series with a resistor 0R1 and break contacts M 14 of the running relay M across the direct-current buses L1 and L2. The break contacts M14 are added to the running relay M of the aforesaid Santini et a1.

patent. Consequently, the capacitoris charged to a voltage dependent on the voltage across the buses.

When the elevator car A starts from the terminal floor at which it is stopped the break contacts M14 open to interrupt the charging circuit of the capacitor BC]. In addition, the make contacts M15 close to connect a period relay 0? across the capacitor 0C1 and the resistor 0R1. The contacts M15 are added to the running relay M of the above-mentioned patent. The period relay 0? picks up and remains picked up for the time required for the capacitor 0C 1 to discharge through the resistor 0R1 and the relay 0? to the dropout voltage of the relay 0?. Consequently, the period relay 0? picks up for a brief period at the start of each trip of the elevator car A.

The elevator car A is equipped with a plurality of switches which indicate different levels of loading of the elevator car. For illustrative purposes, three load switches LMS9, LMS10 and LMS11 are provided and may be operated by the loadmeasuring switch LMS of the above-mentioned Santini et a]. patent. To illustrate suitable parameters, the switch LMS9 may be designed to be biased to closed position and to be opened when the loading of the elevator car reaches 20 percent of rated load. The switch LMS 10 similarly may open when the loading reaches 50 percent of the rated load and the switch LMS11 may be designed to open when the loading reaches percent of rated load.

The three load switches LMS9, LMS10 and LMS11 together with make contacts 0P3 of the period relay 0P are connected in series between the bus L1 and a first contact segment located in one level of an individual load step relay 0881. The second contact segment of this level is connected between the switches LMS9 and LMS10. The third contact segment of this level is connected between the switches LMS10, and LMS11. The fourth contact segment of this level is connected between the contacts 0P3 and the switch LMS11.

The step switch 0851 may be of conventional construction and includes a wiper or brush 0SS1B which is stepped successively from a home position into engagement with the contact segments 1, 2, 3 and 4 in the level or row associated with the brush. In addition, the step switch has self-stepping contacts 088181 and similarly-operated contacts 0SSlS2 (FIG. 7) and 085183 (FIG. 9). When the step switch is at rest, the selfstepping contacts 0SSlS1 are closed. For each step of the step switch, the contacts 08818 to 0SSlS3 briefly open and then reclose. Contacts 0SS1S1 briefly open and then reclose. Contacts 0SSlSl are connected in series with the operating winding of the step switch 0SS1 and the make contacts 0P2 of the period relay 0? across the buses L1 and L2 to provide a selfstepping circuit for the step switch.

A homing switch 055111 is provided for the step switch 0881. This switch is open when the step switch is in its home position as illustrated in FIG. 6. For all other positions of the step switch, the homing switch 0SS1I-I is closed. The homing switch is connected in series with break contacts 0P1 of the period relay 0? across the make contacts 0P2.

Examples of the operation of the step switch 0881 now will be given. The circuits of FIG. 6 indicate that the elevator car A is at rest at a terminal floor and that the capacitor BC! is charged. When the elevator car A is started from the terminal floor the break contacts M14 open to pick up the period relay 0P for a time as above explained. When the period relay 0? picks up it opens its break contacts 0P1 to interrupt the homing circuit of the step switch 0SS1. The make contacts 0P3 close to connect the contact segments of the step switch to the bus L1.

The make contacts 0P2 close to complete a self-stepping circuit for the step switch 0SS1. The first step of this switch carries the brush 0SS1B into engagement with its first contact segment. During this step the self-stepping contacts 0SS1S1 first open and then reclose.

It will be assumed first that the elevator car A is empty. For this condition all of the load switches LMS9 to LMS11 are closed. Consequently, when the brush 0SS1B engages the con tact segment 1 of the associated level a continuous energizing circuit is established for the step switch which may be traced as follows: L1, 6P3, LMSll, LMS10, LMS9, contact segment 1, brush 0551B, 6881, L2. This circuit holds the step switch in the first step position.

At the close of its period, the period relay OP drops out. The resultant opening of the make contacts P2 and OPS interrupts the energizing circuit for the step switch 058 However the closure of the break contacts OPl completes a homing circuit for the step switch which rapidly returns the step switch to its home position.

Let it be assumed next that the elevator car A is loaded to 20 percent of its rate of capacity at the time it leaves its terminal floor. The step switch OSSl steps to its first position in the manner previously described. However, the load switch LMS9 is now open and the step switch cannot be energized therethrough.

The step switch 6881 now steps to its second position in which the brush OSSlB engages its associated contact segment 2. The operating winding of the step switch now is energized through the contacts 0P3 and the switches LMSll and LMS10 to hold the step switch in its second position. During the second step, the self-stepping contacts OSSlSl again open and then close. The step switch remains in its second position until the period relay OP drops out. The step switch then returns to it; home position in the manner previously described. In this way, the step switch for each trip of the elevator car steps a number of times dependent on the loading of the elevator car.

FIGURE 7 The loadings of the elevator cars of the bank O are summed at regular sampling intervals by a step switch OSS2 which has two sets of homing contacts OSS2H1 and OSS2H2. These contacts are open when the step switch is in its home position and are closed when the step switch is away from its home position. The step switch also has a set of self-stepping contacts OSS2S. These contacts are connected in series with the operating winding OSS2 of the step switch, with the homing contacts OSSZHZ and with make contacts ORE4 of an auxiliary sampling relay ORE to establish a self-stepping circuit for the step switch.

The step switch OSS2 in addition has a first level or row wiper or brush OSSZB which is connected to the bus L1 through break contacts ORES of the auxiliary sampling relay ORE. The brush coacts with a first level or row of contact segments which are marked 1 to 40 in FIG. 7. The contact segments are associated with four load-intensity relays O11 to 014. Pickup of the relay O11 indicates a light loading of the bank 6. Picktip of the relays OIZ, O13 and OI4 respectively indicate moderate, heavy and very heavy loading of the bank O.

Contact segments 1 to 10 of the first level of the step switch OSS2 are connected to the bus L2 through the light-load-intensity relay 011. Contact segments ll to 18 are connected to the bus through the operating winding of the moderate-load-intensity relay OI2. Contact segments 19 to 25 are connected to the bus L2 through the operating winding of the heavy-loadintensity relay 613. Contact segments 26 to 40 are connected to the bus L2 through the operating winding of the veryheavy-load-intensity relay OI4.

When the light-load-intensity relay OIl picks up it closes make contacts Oll-l to establish with three rectifiers ORRl to ORR3 and either break contacts OT 3 of a sampling relay OI or break contacts ORE6 of the auxiliary sampling relay ORE a holding circuit. A holding circuit for the relay OI2 is established by make contacts OI2-1, the rectifiers ORR2 and ORR3 and either of the contacts OT 3 or ORE6. For the relay OI3 the holding circuit includes the make contacts 013-1, a rectifier ORR3 and either of the sets of contacts OT 3 or ORE6. Finally, the holding circuit for the relay OI4 includes only the make contacts OI4-l and either of the sets of contacts OT 3 or ORE6.

Any suitable timer may be employed for establishing regular sampling periods for measuring load intensity. In the embodiment illustrated in FIG. 7, a thyratron tube OT A, preferably of the cold cathode type, has its plate or anode connected to the bus L1 through the operating winding of the sampling relay OT and break contacts ORE2 of the auxiliary sampling relay ORE. The plate also is connected to the bus L2 through make contacts OT 1 of the sampling relay OI. A capacitor OC2 is connected to be charged from the conductors L1 and L2 through a charging resistor OR3 and the break contacts ORE2 of the auxiliary sampling relay ORE. The voltage across the capacitor is applied between the grid and cathode of the thyratron tube OT A. A discharge resistor ORZ is connected across the capacitor OC2 through make contacts OREl of the auxiliary sampling relay ORE.

In reviewing the operation of the components shown in FIG. 7, it will be assumed that the auxiliary sampling relay ORE has just dropped out to close its break contacts OREZ thus connecting the capacitor 0C2 and the charging resistor 0R3 in series across the direct current buses LI and L2. The capacitor now starts to charge at a rate determined by the sizes of the capacitor and the charging resistor, At the end of a predetermined time, for example two minutes, the voltage across the capacitor becomes sufficient to fire the thyratron tube OT A and such firing results in energization and pickup of the sampling relay OT When it picks up, the sampling relay closes its holding con tacts OT! to complete with the break contacts ORE2 a holding circuit for the sampling relay. In addition, the break contacts OT 3 open to interrupt the holding circuits for the load-intensity relays OII to Ol4.

If the bank load step relay OSS2 is in its home position, the

homing contacts OSS2H1 are open and closure of the make contacts OT 2 of the sampling relay OT at this time has no effect on the system. However, if the step relay is away from its home position, the contacts OSS2H1 are closed and closure of the contacts OT 2 consequently completes an energizing circuit for the auxiliary sampling relay ORE.

Pickup of the auxiliary sampling relay ORE results in closure of its self-holding contacts ORE3 which complete a holding circuit through the homingcontacts OSS2H1. Consequently,

the auxiliary sampling relay remains picked up until the step switch returns to its home position. In addition, the break contacts ORE2 open todrop out the sampling relay HI, and make contacts OREl close to establish a discharge circuit for the capacitor OC2 through the discharge resistor OR2. Closure of Y the make contacts ORE4 completes a self-stepping circuit for the step relay OSS2 through the homing contacts OSS2H2 and the self-stepping contacts OSSZS. Consequently the step relay new steps to its home position where the contacts OSSZHZ' open to interrupt the homing circuit. Opening of the break contacts ORES disconnects the brush OSSZB of the step relay from the associated bus L1. to prevent energization therethrough of the load-intensity relays while the step switch IS resetting.

Let it be assumed that immediatelybefore the relay OT picks up the brush OSSZB was engaged with the contact segment 19, that all four load-intensity relays 011 to ON had been; energized during the receding sampling period and that they were being held in by the break contacts OT 3. When the relay.

OT picks up, the break contacts HI 3 open to interrupt the holding circuits for the load-intensity relays. This results in deenergization and drop out of the load intensity relay Old. However, the load-intensity relays OH to O13 continue to be held in picked up condition through the break contacts ORES.

picked up the three load-intensity relays OH to Ol3. Thus, the load represented by the pickup of these three load-intensity relays is stored for the duration of the next sampling period which is terminated by the next pickup of the sampling relay It will be recalled that pickup of the auxiliary sampling relay ORE is followed by drop out of the sampling relay T. In dropping out, the sampling relay opens it holding contacts 6T I to prepare for a subsequent timing operation. In addition, the break contacts 9T3 close to maintain the holding circuit for any of the load-intensity relays which may be picked up at this time. The make contacts 0T2 reopen but the closed make contacts 0RE3 maintain a holding circuit for the auxiliary sampling relay ORE until the step relay 0SS2 reaches its home position to open the homing contacts OSSZH 1.

During the time required for the capacitor 0C2 to recharge to a voltage sufficient to again fire the thyratron tube OT A each car of the feeder bank 6 leaving a terminal floor with substantial load supplies pulses to the step relay OSSZ. Thus when the elevator car A leaves a terminal floor, the make contacts 0P4 of the period relay 0? close for a time sufficient to measure the load in the elevator car. It will be recalled that during this time the contacts 0SS1S2 of the step switch OSSl close and reopen a number of times dependent on the load carried by the elevator car during this period, and each closure produces a pulse which advances the step switch 0SS2 through one step. Inasmuch as similar pulse circuits are provided for each of the elevators of the bank 6 it follows that the step switch 8852 is advanced through a number of steps in each of its sampling periods which corresponds to the total load carried by the bank 0 during such period.

It is possible that two or more cars of the bank 0 may apply pulses to the step relay OSSZ at the same time. The probability of the occurrence of such coincident pulses is small and may be neglected for practical purposes. However, if desired, conventional anticoincident circuits may be employed for assuring the application of one pulse to the step relay 0852 for each operation of the contacts OSSISZ to DOSSISZ.

If the traffic follows a reasonably regular pattern each day or each week the load-intensity relays Oil to GM may be operated by a time switch or clock 6T S. To illustrate such operation, the four switches OSWI to 0SW4 may be operated to their lower positions as viewed in FIG. 7. This connects the load-intensity relays to contacts of the time switch 0T S for the purpose of energizing at each instant the load-intensity relays corresponding to the expected load for such instant.

FIGURE 8 In FIG. 8 circuits are shown for controlling the number of elevators in the feeder bank 0 which are in service. If the bank has more elevators in service than are required a surplus-car relay OQMGI picks up to decrease the number of elevator cars in service. If the number of elevators in service is insufficient a deficit-car relay OQMGZ picks up to increase the number of elevators in service.

The relays OQMGI and OQMGZ are controlled by a bridge circuit which includes five resistors 0R4 and (R7 to 0Rl0 connected in series across the direct-current buses L1 and L2. Five additional resistors 0R5, 0R6, B6R6, and DOR6 are connected in series across the buses L1 and L2. Each of the relays GQMG] and 0QMG2 is connected in series with a separate rectifier ORR? or ORRS between a point located intermediate the resistors 0R4 and 0R7 and a point intermediate the resistors 0R5 and (R6. The resistors 0R4 and 9R5 represent two arms of the bridge. A third arm contains the resistors 0R7 to 0Rl0 in series. The remaining arm of the bridge contains the resistors 0R6 to DOR6 in series. The resistors 0R4 and 0R5 may have equal resistance values. The remaining resistors each may have a resistance value equal to one-fourth the resistance value of the resistor 0R4.

The rectifiers 0R4 and 0R5 are oppositely directed. As long as the bridge is balanced both of the relays OQMGI and OQMGZ are dropped out and no change is made in the number of elevators in service. The resistors 6R7 to (R10 are shunted respectively by break contacts 011-2 to 014-2 of the load-intensity relays. The resistors 0R6 to DOR6 are shunted respectively by break contacts MG8 to DMG8 of the motor-generator starting switches for the four elevator cars.

Break contacts MGIO to DMGIO of the four motor-generator starting switches are connected in series with an auxiliary motor-generator relay OMGA across the buses L1, L2 through a parallel circuit having four arms containing respectively break contacts 78-6 to D78-6 of the no-call relays 78 to D78.

The operating winding of the motor-generator starting switch MG is connected across the buses L1 and L2 through make contacts NL8 of the lower-terminal next relay and make contacts OQMGZ-l of the deficit-car relay OQMGZ. When the motor-generator starting switch picks closes it closes its make contacts MG9 to establish a holding circuit which is completed through any one of three sets of contacts; namely, make contacts M16 of the running relay M, break contacts NL9 of the lower-terminal next relay and break contacts QQMGI-I of the surplus-car relay. Similar circuits are shown for the motor-generator starting relay BMG for the elevator B and similar circuits (not shown) are provided for each of the remaining motor-generator starting relays.

If a call is registered (at least one set of contacts 78-6 to D78-6 is closed) while no motor-generator set is running (contacts MGIO to DMGIO are closed) the auxiliary motorgenerator relay GMGA picks up to shunt the contacts OQMGZ-l to 0QMG2-4 thus permitting starting of a next car to answer the call. Registration of a call is indicated by energization of one of the floor or car call registering relays of FIG. 3, and by the resultant drop out of one of the no-call relays 78 to D78 in the manner discussed in the above-mentioned patent.

Let it be assumed that the load is very heavy and that all of the load-intensity relays OII to GM are picked up. Let it be assumed further that all of the elevators of the feeder bank 6 are in operation and that the motor-generator starting switches for these elevators consequently are all picked up. Under these circumstances, all of the resistors in the bridge are effectively in circuit and the bridge is balanced. Therefore, the surpluscar relay BQMGI and the deficit-car relay 8QMG2 are both dropped out.

Let it be assumed next that the load-intensity drops to a value such that the load-intensity relay 014 drops out to close its break contacts 014-2 and that the remaining load-intensity relays remain picked up. Under these circumstances the resistor (R10 is effectively removed from the bridge circuit. The bridge now is unbalanced in a direction such that the surpluscar relay GQMGI picks up to open the break contacts OQMGl-l in the circuits of the motor-generator starting switch MG of the elevator A and similar contacts located in the circuits for the motor-generator starting switches of the other elevators.

After the pickup of the relay BQMGI it will be assumed that the elevator car A is selected as the next car to leave the main floor. Under such circumstances, the make contacts M16 of the running relay M are open for the reason that the car has not yet started. The break contacts of the lower-terminal next relay NL9 are open. The make contacts BQMGZ-I of the deficit-car relay and the contact OMGAI of the auxiliary motor-generator relay are open. This interrupts the energization of the motor-generator starting switch MG and this switch drops out to remove the elevator car A from service.

In dropping out, the motor-generator starting switch MG closes its break contacts MG8 to effectively remove the resistor 0R6 from the bridge circuit. The bridge now is restored to balance and the surplus-car relay OQMGl drops out to reclose its break contacts 0QMGl-l and similar contacts for the other cars of the bank. Therefore, no other elevator in the bank will be removed from service as long as the bridge remains in balance.

Let it be assumed now that the load intensity increases until the load-intensity relay 0l4-2 again picks up to reopen its break contacts 0I4-2. This effectively restores the resistor 0R10 to the bridge. Inasmuch as the motor-generator starting switch MG remains dropped out, the break contacts MG8 are still closed and the resistor 0R6 effectively is out of the bridge. For these reasons the bridge is unbalanced in the opposite direction and the deficit-car relay 0QMG2 picks up to close its make contacts QMG2-l and similar contacts in the circuits of the motor-generator starting switches for the other elevators of the bank. When the elevator car A is again selected as the next elevator car to leave the main floor and make contacts NL8 of the lower-terminal next relay NL close to complete an energizing circuit for the motor-generator starting switch MG. This restores the elevator A to service. When it picks up, the motor-generator starting switch MG opens its break contacts MG8 to place the resistor 6R6 effectively in the bridge. This rebalances the bridge and causes the deficit car relay QMG2 to drop out. This relay thereupon opens its make contacts 6QMG2- l and similar contacts associated with the motor-generator starting switches of the remaining cars of the'bank.

As shown in the aforesaid Santini et al. patent, the dispatcher for the lower-terminal floor is so arranged that an elevator car at the lower-tenninal floor having its motorgenerator set in operation is selected as a next car in preference to an elevator car which has its motor-generator set shut down. This means that if the elevator A is shut down at the lower-terminal floor another elevator will have its car selected as the next car to leave the lower-terminal floor unless no other elevator car with its motor-generator set in operation is located at the main floor.

FIGURE 9 The divisional index ODl is shown in greater detail in FIG. 9. It comprises a two-way step switch having a first operating winding OSST and a second operating winding HSSB. Each pulse applied to the winding OSST notches the pointer 0DlP in a clockwise direction for one step. Each pulse applied to the winding ()SSB notches the pointer ODIP one step in a counterclockwise direction. l-loming contacts OSSl-l are operated to open condition only when the pointer ()DlP occupies its center position as indicated in FIG. 9. At its end, the pointer ODIP has a wiper or brush which coacts with a level or row of contact segments bearing the numbers 1 to 19.

The winding 0388 is connected across the buses L1 and L2 through any one of four similar parallel circuits one for each of the elev ators of the feeder bank 0. Thus, for the elevator A, the winding 0888 is connected across the buses through make contacts W14 of the up'direction relay W, contacts 958183 of the individual-load step relay 0881 and make contacts 6P5 of the period relay 0P. Similar circuits are shown for the remaining cars of the bank. Thus during a sampling period, the winding OSSB receives a number of pulses which corresponds to the loadings of the elevator cars during up trips.

in a similar manner, the winding OSST receives a number of pulses corresponding to the loadings of the cars during down trips. For example, for the elevator car A, the winding OSST is connected across the direct-current buses L1 and L2 through make contacts X14 of the down-direction relay X, contacts 0SS1S3 associated with the individual-load step relay 6SSl and make contacts 0P5 of the period relay 6?. A similar circuit is shown for each of the elevators of the feeder bank 0.

The sampling period for the divisional index ODI is determined by the auxiliary sampling relay ORE. This relay has make contacts 0RE7 which connect the winding OSSB across the buses L1 and L2 through the homing contacts OSSl-l and the self-stepping contacts OSSBS. Consequently at the end of each sampling period the contacts, 0RE7 close to step the divisional index 0D! to its home position.

Engagement of the pointer GDIP with any of the contact segments 1, 2 and 3 indicates a heavy preponderant movement of traffic up from the main floor. Engagement of the pointer with any of the contact segments 4 to 7 indicates a moderate preponderant movement of traffic from the main floor in an up direction. Engagement of the pointer with any of the contact segments 8 to 12 indicates that traffic components leaving the sky lobby and the main floor are substantially equal or balanced. Engagement of the pointer with any of the contact segments 13 to 16 indicates a moderate preponderant flow of traffic down from the sky lobby. Engagement of the pointer with any of the contact segments 17 to 19 indicates a relatively heavy preponderant movement of traffic from the sky lobby. Other zone arrangements may be employed if desired.

In many applications, it is desirable to bias the divisional index ODl in accordance with the load moved by the local banks towards the sky lobby. Thus each loaded car in the local bank traveling down towards the sky lobby may be arranged to supply a predetermined number of pulses to the winding GSST. ln H6. 9, the winding OSST is additionally connected across the buses Li and L2 through any one of a number of parallel circuits one for each of the local cars. For the car A in the bank 1 the winding OSST is connected across the buses through the contacts DPl of a period relay DP make contacts 1 X14 of a down direction relay DX and contacts l LMS8 of a load switch in series. The contacts 1 Pl close for a short time when the elevator car A of the bank b starts down. The contacts l Xl4 are closed while the elevator car A of the bank i is set for down travel. The contacts LMS8 are closed while the elevator car A of the bank I is loaded to a predetermined extent such as percent of rated capacity. If the elevator car A of the bank D while loaded starts down, a pulse will be delivered to the winding OSST to actuate the divisional index 0Dl.

As pointed outbelow the contacts 084-1 of FIG. 9 close for a heavy preponderant movement of traffic from the main floor towards the sky lobby. On closure of these contacts, one or more of the local banks may expedite the movement of elevator cars to the sky lobby. In FIG. 9, closure of the contacts 684-1 connects the high call reversal relay DHCM for the bank 1 across the buses L1 and L2. The relay HCM corresponds to the relay HCM of the aforesaid Santini et al. patent and operates in the same way to expedite movement of the associated elevator cars to the sky lobby. Contacts of the relay 0B4 similarly may control a relay corresponding to the relay HCM for each of the other local banks. A number of controlling components in circuits of the relay DHCM as shown in the present FIG. 9 and are identified by .the same reference characters employed for similar components for the relay HCM in said patent, but preceded by the prefix 1 FIGURE 10 In FIG. 10, divisional load relays 0B4, 0B3, OBAL, 0T L3 and 01 L4 are responsive to the relation between traffic moving up from the main floor and traffic moving down from the sky lobby. The pointer ODlP is connected to the positive bus L1 through make contacts (71" 4 of the sampling relay Ul" and break contacts 6RE9 of the relay ORE. Pickup of the relay 084 indicates a heavy preponderance of traffic away from the main floor towards the sky lobby. This relay is connected between the negative bus L2 and the three contact segments 1, 2 and 3 of the divisional index 0D] when the switch BSWS is in its upper position.

The relay 0B3 picks up to indicate a moderate preponderance of traffic away from the main floor towards the sky lobby and is connected between the bus L2 and the contact segments 4 to 7 when the switch 0SW6 is in its upper position.

The relay OBAL when picked up indicates a substantially balanced traffic condition. It is connected between the bus L2 and the contact segments 8 to 12, when the switch 0SW7 is in its upper position.

When picked up, the relay HILJ indicates a moderate preponderance of traffic from the sky lobby towards the main floor. It is connected between the bus L2 and the contact segments 13 to 16 when the switch (SW8 is in its upper position.

Pickup of the relay 6T L4 indicates a heavy preponderance of traffic from the sky lobby towards the main floor. This'relay is connected between the bus L2 and the contact segments l7,

l8 and 19 when the switch 0SW8 is in its upper position.

A holding circuit for the relay 084 is established througheither break contacts 6T5 of the sampling relay GT or make contacts RE8 of the auxiliary sampling relay ORE, a rectifier 0RR6 and make contacts 084-2. A holding circuit for the relay 083 extends through either the contacts 9T5 or the contacts 6RE8, a rectifier 0RR7 and make contacts 083-1. For the relay OBAL a holding circuit extends through either the contacts 6T5 or the contacts ORES, a rectifier 0RR8 and make contacts OBAL 1. A holding circuit for the relay 0T L3 extends through the contacts 6T5 or the contacts ORES, a rectifier 0RR9 and make contacts 0TL3-l, For the relay 0TL4, a holding circuit extends through either the contacts 6T5 or the contacts (IRES, a rectifier 0RR10 and contacts 6TL4-1.

To illustrate the operation of this circuit, let it be assumed that at the beginning of the sampling period the relay OBAL is energized through the holding circuit: Ll, 0T5, 6RR8, BBALl, 0S\V7, BBAL, L2. Let it be assumed further that during the sampling period the pointer ODIP moves into engagement with the contact segment 6. At the end of the sampling period, the break contacts 6T5 open to deenergize the relay OBAL. In addition, the make contacts 9T4close to complete an energizing circuit for the relay 083. The relay 6133 then closes its make contacts 0133-1 to prepare the holding circuit of this relay for subsequent completion. Shortly afterwards, the auxiliary sampling relay ORE picks up to close its make contacts ORES and thus completes a holding circuit for the relay 683. Also break contacts 0RE9 open to prevent false pick up of a divisional load relay during reset of the two-way step switch. (These contacts could be omitted if the sequence is such that the relay 6T always drops out before the two-way step switch starts to move at the start of a resetting operation). The relay 01" then drops out to close its break contacts 0T5 for the purpose of maintaining the holding circuit when the contacts 6RE8 subsequently open. In addition, the make contacts 0T 4 open to disconnect the pointer ODIP from the bus L].

If the traffic flow follows a regular pattern from day to day or from week to week the relays of FIG. 10 may be operated from a time switch or clock GISl. Switches OSWS to 6SW9 are provided for the purpose of switching the relays to the time switch. When so switched, the time switch picks up the proper relay for the proper period of time.

FIGURE l 1 In FIG. 11, two up-car relays 0U2 and 0U3 are responsive to the number of elevators in the feeder bank 6 which are set for up travel. These relays are connected in parallel for energization through one or more of four parallel circuits, one for each of the elevators. Thus for the elevator A one of the circuits contains in series make contacts a8 of the up switch U and a resistor 6R1]. It will be understood that the make contacts U8 are operated by the up switch U of the aforesaid Santini et al. patent. The resistors 0R1! to DORll for the four elevators have equal resistance values.

The pickup point of the up-car relay 0U2 is adjusted by means of an adjustable resistor 0R14 which is connected across the operating winding of the relay. For present purposes it will be assumed that the relay is adjusted to pick up when energized through two or more of the resistors (R11 to DOR11. It is dropped out when energized through only one of these resistors.

In a similar manner, an adjustable resistor 6R13 is connected across the operating winding of the up-car relay 0U3 for the purpose of adjusting the pickup point of this relay. For present purposes, it will be assumed that this relay picks up when energized through three or more of the resistors 6R1 1 to DBRll. It is dropped out when energized through only two of these resistors.

Various procedures are available for dispatching elevator cars from the terminal floors. For example, an elevator car selected as the next car to leave a terminal floor may be dispatched a predetermined time after the preceding car was dispatched, or in dependence on positions of other cars, or under certain load conditions, or in response to assignment to answer a specific call registration, or after selection. The

relays 01 and 62 are intended to allocate a proportion of cars in each direction of travel, depending on where the traffic originates.

The relay 01 may be so arranged that when picked up it permits or expedites the dispatch of elevator cars from the main floor and when dropped out it prevents the dispatch of cars from the main floor or delays such dispatch.

In the illustrated embodiment of the invention, the relay 01 has make contacts 01-1 connected across the make contacts 1SU3 (FIG. 5 Let it be assumed that traffic is in the balanced range wherein the divisional load relay OBAL is picked up. Let it be assumed further that the only one elevator car is traveling up. The relay 61 now is picked up and closes its make contacts 01-1 (FIG. 5). This cuts out the dispatching interval at the main floor and the next car at the main floor is started up provided that its noninterference relay is dropped out to close its break contacts T4 (FIG. 3A). As shown in the aforesaid Santini et al. patent, this relay 70T drops out after a short time delay such as 5 seconds measured from the stopping of the associated elevator car at the main floor.

Assuming that the elevator car B has been running up and that the car A has just been started up, make contacts U8 and BU8 (FIG. 11) are closed and the up-cars relay 0U2 picks up. This relay opens its break contacts 0U2-1 to deenergize the up dispatcher expedite relay 61 which opens its make contacts 61-1 (FIG. 5) to restore the effectiveness of the contacts ISU 3 of the lower-interval holding relay ISU. Consequently another elevator car cannot be started from the main floor until the dispatching interval has expired.

Let it be assumed next that traffic conditions are such that the preponderance of traffic traveling from the sky lobby to the main floor is moderately heavy and that the relay 011.3 consequently is picked up to close its contacts UT L 3-2. If we again assume that only one of the elevator cars is traveling up break contacts GUS-l of the up-cars relay BUS is dropped out and the up dispatcher expedite relay 8 is picked up through the contacts UI'LS-Z and 0U3-1. This closes the contacts 91-1 (FIG. 5) to expedite the dispatch of elevator cars from the main floor. If a second car starts from the main floor, while the first car is still running up, the up-cars relay 6U2 picks up to open its break contacts 6U2-1. This has no immediate effect on the operation of the system. However, if a third car is started from the main floor while the first and second cars are traveling up, the up-cars relay 6U3 picks up to open its break contacts GUS-1. This drops out the up dispatcher expedite relay 01 which opens its make contacts 61-1 (FIG. 5) to require a subsequent elevator car at the main floor to wait for its dispatching interval before it can be started up.

Let it be assumed next that the preponderance of trafi'tc from the sky lobby to the main floor is very heavy and that the divisional load relay OTL 4 consequently is picked up. This relay closes its make contacts HTL4-2 to energize the up dispatcher expedite relay 61 which closes its make contacts 01-1 (FIG. 5). Elevator cars are now expedited away from the main floor towards the sky lobby where they are needed until the divisional index operates to deenergize the divisional load relay 6114 to indicate that the heavy down trafi'lc condition has subsided.

Similar circuits are provided for controlling the dispatch of elevator cars from the sky lobby towards the main floor. Thus, down-cars relays 0D2 and 0D3 are connected in parallel for energization through one or more parallel circuits one for each of the elevator cars. For the elevator car A one of the parallel circuits includes make contacts D8 of the down switch D and a resistor ORIS. Adjustable resistors 0R16 and (R17 are connected respectively across the operating windings of the relays 6D3 and 6D2 for the purpose of adjusting the pickup points of these relays. For illustrative purposes, it is assumed that the relay 0D2 is adjusted to pick up when energized through two of the resistors 0R15 to DORIS and to drop out when energized through only one of these resistors. The relay 6D3 is arranged to pick up when energized through three of these resistors and to be dropped out when energized through only two of the resistors.

When the divisional load relay OBAL is picked up, its make contacts 0BAL3 close to energize the down dispatcher expedite relay 02 through the break contacts 0D2-1 and 9D3-1. This expedites dispatch of elevator cars down from the sky lobby in an effort to make two cars run down in the same manner by which closure of the make contacts OBAL 2 picked up the up dispatcher expedite relay 01 to expedite dispatch of elevator cars from the main floor until two cars were running up as outlined above.

If the divisional index registers a moderate preponderant flow of traffic from the main floor towards the sky lobby, the divisional load relay 0B3 picks up to close its make contacts OBS-2. This energizes the down dispatcher expedite relay 02 through the contacts 683-2 and through the break contacts 0D3-l of the down cars relay (D3. The relay 02 now expedites the dispatch of elevator cars from the sky lobby towards the main floor where they are needed until three cars set for down travel pick up the down-cars relay 0B3 to open the break contacts ODS-l This operation is similar to that resulting from closure of the make contacts 0113-2 which is discussed above for the opposite traffic fiow.

In the presence of a heavy flow of traffic from the main floor towards the sky lobby the make contacts 084-3 close to pick up the down dispatcher expedite relay 02. This expedites the dispatch of elevator cars from the sky lobby floor towards the main floor until the down traffic flow decreases sufficiently to result in opening of the make contacts 0B4-3.

SUMMARY In summary, the bridge circuit of- FIG. 8 compares the number of cars in service in the feeder bank 0 with the intensity of traffic for the purpose of controlling the surplus-car relay OQMGl and the deficit-car relay BQMGZ. If more cars are in service than are required to handle the traffic, the relay OQMGI operates to shut down the motor-generator sets of the surplus elevator cars. Such cars of course are then available to help out an adjacent feeder bank if required.

If the number of cars in service is insufficient to handle the existing traffic, the relay OQMGZ picks up for the purpose of starting m otor-generator sets.

The divisional index compares traffic from the sky lobby to the main floor with traffic from the main floor to the sky lobby. The direction and magnitude of the difference is indicated. if desired, traffic traveling towards the sky lobby in the local banks may modify the registration of the divisional index. The divisional index is employed for controlling the allocation of cars in the feeder bank to the sky lobby and to the main floor in order to handle traffic most efficiently. If desired, the divisional index may be utilized to expedite return of elevator cars in the local banks to the sky lobby under certain traffic conditions.

If the flow of traffic follows a repetitive pattern on a daily or weekly basis, the number of elevator cars in service, the allocation of cars to the sky lobby and the main tenninal and the expediting of cars towards the sky lobby may be controlled by time clocks or time switches.

We claim:

1. A conveyor arrangement for a structure having a plurality of landings comprising a plurality of vehicles for transporting load between said landings, means for each of said vehicles for generating pulses of a quantity dependent in number on the loading of the associated one of the vehicles, means for counting a function of the numbers of said pulses, and control means responsive to said function for controlling said vehicles.

2. A conveyor arrangement as claimed in claim 1, wherein said control means comprises comparison means responsive to the difference between the total number of said pulses and the number of said vehicles in service for controlling the number of the vehicles in service.

3. A conveyor arrangement as claimed in claim 2 wherein said comparison means comprises first directional means responsive to a first direction of unbalance between said total number and the number of the vehicles in service for increasing the number of vehicles in service, and second directional means responsive to a second direction of unbalance between said total number and the number of the vehicles in service for decreasing the number of vehicles in service.

4. A conveyor arrangement for a structure having a first landing and a second landing, a conveyor system having a plurality of first vehicles mounted for movement between the first and second landings as terminal landings for transporting load therebetween, control means for moving the vehicles between the first and second landings without intermediate stops, period-determining means for establishing a first period for a first proportioning of the vehicles to the landings and a second period for a second proportioning of the vehicles to the landings, and distribution means responsive to said perioddetermining means for establishing a first proportioning of said vehicles to each of said landings during said first period and a second proportioning of said vehicles to each of said landings during said second period.

5. A conveyor arrangement as claimed in claim 4 wherein said period-determining means comprises load-responsive means for establishing said first and second periods in dependence on load originating at each of the landings.

6. A conveyor-arrangement as claimed in claim 4 wherein said period-determining means includes load-responsive means for measuring the load in each of the vehicles leaving each of the landings, and said distribution means is responsive.

to the measurements by said load-responsive means for dividing between the first and second landings allocations of the vehicles in accordance with the difference in loads leaving the first and second landings.

7. A conveyor arrangement as claimed in claim 6'wherein said landings are vertically spaced from each other, said vehicles being elevator cars mounted for vertical movement between the landings, said load-responsive means comprising means for producing a number of first pulses ofa quantity dependent on the magnitude of the load in each of the elevator cars leaving the first landing, and means for producing a number of second pulses of a quantity dependent on the magnitude of the load in each of the elevator cars leaving the second landing, and said proportioning means comprising means for expediting to the first and second landings first and second numbers of said elevator cars dependent on the difference between the numbers of said first and second pulses.

8. A conveyor arrangement as claimed in claim 4 wherein said structure comprises a plurality of floors in a zone including a first floor providing said first landing, a second floor providing said second landing and a plurality of intermediate floors located between said first and second floors, and comprises a plurality of additional floors located on one side of said zone, an additional vehicle mounted for movement relameans for measuring the load in each of the vehicles leaving 7 each of the landings, and said distribution means is responsivev to the measurements by said load-responsive means for dividing between the first and second landings allocations of the vehicles in accordance with the difference in loads leaving the; first and second landings, said floors being vertically spaced from each other, said vehicles being elevator cars mounted for vertical movement between the floors, said load-responsive means comprising means for producing a number of first pulses of a quantity dependent on the magnitude of the load in each of the first vehicles leaving the first landing, and means.

for producing a number of second pulses of a quantity dependent on the magnitude of the load in each of the first vehicles: leaving the second landing, and said proportioning means comprising means for expediting to the first and second landings first and second numbers of said first vehicles depen-.

dent on the difference between the numbers of said first and second pulses. 

1. A conveyor arrangement for a structure having a plurality of landings comprising a plurality of vehicles for transporting load between said landings, means for each of said vehicles for generating pulses of a quantity dependent in number on the loading of the associated one of the vehicles, means for counting a function of the numbers of said pulses, and control means responsive to said function for controlling said vehicles.
 2. A conveyor arrangement as claimed in claim 1, wherein said control means comprises comparison means responsive to the difference between the total number of said pulses and the number of said vehicles in service for controlling the number of the vehicles in service.
 3. A conveyor arrangement as claimed in claim 2 wherein said comparison means comprises first directional means responsive to a first direction of unbalance between said total number and the number of the vehicles in service for increasing the number of vehicles in service, and second directional means responsive to a second direction of unbalance between said total number and the number of the vehicles in service for decreasing the number of vehicles in service.
 4. A conveyor arrangement for a structure having a first landing and a second landing, a conveyor system having a plurality of first vehicles mounted for movement between the first and second landings as terminal landings for transporting load therebetween, control means for moving the vehicles between the first and second landings without intermediate stops, period-determining means for establishing a first period for a first proportioning of the vehicles to the landings and a second period for a second proportioning of the vehicles to the landings, and distribution means responsive to said period-determining means for establishing a first proportioning of said vehicles to each of said landings during said first period and a second proportioning of said vehicles to each of said landings during said second period.
 5. A conveyor arrangement as claimed in claim 4 wherein said period-determining means comprises load-responsive means for establishing said first and second periods in dependence on load originating at each of the landings.
 6. A conveyor-arrangement as claimed in claim 4 wherein said period-determining means includes load-responsive means for measuring the load in each of the vehicles leaving each of the landings, and said distribution means is responsive to the measurements by said load-responsive means for dividing between the first and second landings allocations of the vehicles in accordance with the difference in loads leaving the first and second landings.
 7. A conveyor arrangement as claimed in claim 6 wherein said landings are vertically spaced from each other, said vehicles being elevator cars mounted for vertical movement between the landings, said load-responsive means comprising means for producing a number of first pulses of a quantity dependent on the magnitude of the load in each of the elevator cars leaving the first landing, and means for producing a number of second pulses of a quantity dependent on the magnitude of the load in each of the elevator cars leaving the second landing, and said proportioning means comprising means for expediting to the first and second landings first and second numbers of said elevator cars dependent on the difference between the numbers of said first and second pulses.
 8. A conveyor arrangement as claimed in claim 4 wherein said structure comprises a plurality of floors in a zone including a first floor providing said first landing, a second floor providing said second landing and a plurality of intermediate floors located between said first and second floors, and comprises a plurality of additional floors located on one side of said zone, an additional vehicle mountEd for movement relative to the structure for serving said additional floors, and control means for moving said additional vehicle to carry load between said additional floors and one of said landings.
 9. A conveyor-arrangement as claimed in claim 8 wherein said period-determining means includes load-responsive means for measuring the load in each of the vehicles leaving each of the landings, and said distribution means is responsive to the measurements by said load-responsive means for dividing between the first and second landings allocations of the vehicles in accordance with the difference in loads leaving the first and second landings, said floors being vertically spaced from each other, said vehicles being elevator cars mounted for vertical movement between the floors, said load-responsive means comprising means for producing a number of first pulses of a quantity dependent on the magnitude of the load in each of the first vehicles leaving the first landing, and means for producing a number of second pulses of a quantity dependent on the magnitude of the load in each of the first vehicles leaving the second landing, and said proportioning means comprising means for expediting to the first and second landings first and second numbers of said first vehicles dependent on the difference between the numbers of said first and second pulses. 